RpcDataSource.java revision 6bc47015cce0ebc2fc255d3950bfeaf4851f36fd 
1package autotest.common.table;
2
3import autotest.common.JsonRpcCallback;
4import autotest.common.JsonRpcProxy;
5import autotest.common.Utils;
6
7import com.google.gwt.json.client.JSONArray;
8import com.google.gwt.json.client.JSONNumber;
9import com.google.gwt.json.client.JSONObject;
10import com.google.gwt.json.client.JSONString;
11import com.google.gwt.json.client.JSONValue;
12
13/**
14 * Data source that retrieves results via RPC requests to the server.
15 */
16public class RpcDataSource implements DataSource {
17    protected String getDataMethod, getCountMethod;
18    protected JSONObject filterParams;
19    protected Integer numResults = null;
20
21    public RpcDataSource(String getDataMethod, String getCountMethod) {
22        this.getDataMethod = getDataMethod;
23        this.getCountMethod = getCountMethod;
24    }
25
26    /**
27     * Process the JSON result returned by the server into an array of result
28     * objects.  This default implementation assumes the result itself is an array.
29     * Subclasses may override this to construct an array from the JSON result.
30     */
31    protected JSONArray handleJsonResult(JSONValue result) {
32        return result.isArray();
33    }
34
35    public void updateData(JSONObject params, final DataCallback callback) {
36        filterParams = params;
37        JsonRpcProxy.getProxy().rpcCall(getCountMethod, params,
38                                        new JsonRpcCallback() {
39            @Override
40            public void onSuccess(JSONValue result) {
41                int count = (int) result.isNumber().doubleValue();
42                numResults = Integer.valueOf(count);
43                callback.onGotData(count);
44            }
45        });
46    }
47
48    public void getPage(Integer start, Integer maxCount,
49                        String sortOn, Integer sortDirection,
50                        final DataCallback callback) {
51        JSONObject params;
52        if (filterParams == null)
53            params = new JSONObject();
54        else
55            params = Utils.copyJSONObject(filterParams);
56        if (start != null)
57            params.put("query_start", new JSONNumber(start.intValue()));
58        if (maxCount != null)
59            params.put("query_limit", new JSONNumber(maxCount.intValue()));
60        if (sortOn != null) {
61            if (sortDirection.intValue() == DataSource.DESCENDING)
62                sortOn = "-" + sortOn;
63            JSONArray sortList = new JSONArray();
64            sortList.set(0, new JSONString(sortOn));
65            params.put("sort_by", sortList);
66        }
67
68        JsonRpcProxy.getProxy().rpcCall(getDataMethod, params,
69                                        new JsonRpcCallback() {
70            @Override
71            public void onSuccess(JSONValue result) {
72                JSONArray resultData = handleJsonResult(result);
73                callback.handlePage(resultData);
74            }
75        });
76    }
77
78    public int getNumResults() {
79        assert numResults != null;
80        return numResults.intValue();
81    }
82}
83